7 medical reasons that could explain why you're tired all the time

Because it's not just about how much sleep you've had...

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GettyTim Robberts

By Rachel Burge

2 April 2017

You're often so tired you struggle to get through the day and by bedtime you're exhausted. Doctors call it 'TATT' – tired all the time. If that sounds like you, read on to discover seven medical issues that could be to blame.

1. Low mood and depression

Depression doesn't just make you feel low – it can cause a range of physical symptoms, including headaches, general aches and pains, and chronic tiredness.

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'Low mood and depression is one of the leading causes of fatigue,' says Dr Marieke Reddingius, a GP in East Sussex.

'Emotional exhaustion can often present itself as physical feelings of tiredness. Even though you're tired, staying active can help to lift your mood.'

If you've been extremely tired for weeks and feel sad or hopeless, or have lost interest in the things you once enjoyed, it's worth seeing your GP.

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'Some people see their doctor because they feel low or tearful, but for others, tiredness can be the main presenting symptom of depression,' says Dr Reddingius

2. Anxiety or stress

Anxiety is another common cause of tiredness, particularly if worries are preventing you from falling asleep at night or causing you to wake early.

'When you perceive danger, your body reacts by going into 'flight or fight' mode – your heart rate increases and adrenaline is released, helping you to flee or fight the threat. You don't have to be facing a sabre-tooth tiger – the response can just as easily be triggered by worrying about work,' says Dr Reddingius.

'When you're chronically anxious, your body is in a permanent cycle of adrenaline rush/adrenaline crash, leading to feelings of exhaustion.'

3. Iron deficiency

Iron deficiency anaemia is one of the most common medical causes of tiredness, particularly in women who have heavy periods. Other symptoms can include heavy-feeling muscles, heart palpitations and shortness of breath. 'Iron is needed to make haemoglobin, the substance that makes blood red and carries oxygen around the body. Even if you're not anaemic, low iron can cause you to feel lacking in energy,' says Dr Reddingius.

Dr Reddingius advises not to drink tea for 30 minutes before or after eating. 'It prevents your body from taking the iron from your food. If you eat/drink something that contains vitamin C, it helps with the uptake of iron.'

4. Vitamin B12 deficiency

A lack of vitamin B12 can also cause you to feel tired. Other symptoms of B12 deficiency include pins and needles, muscle weakness, disturbed vision, a sore and red tongue, mouth ulcers, memory problems and depression.

Eating more meat, fish, eggs, dairy products and yeast extract like Marmite may help, although diet is not commonly to blame. As Dr Reddingius explains:

'In most cases it is caused by pernicious anaemia – where your immune system attacks healthy cells in your stomach, preventing your body from absorbing vitamin B12 from the food you eat. Certain medication, such as anticonvulsants and proton pump inhibitors, can also affect how much of these vitamins your body absorbs.

'However, not all people with low B12 will have anaemia, and tiredness can be the only presenting symptom. Vitamin B12 deficiency can be diagnosed with a blood test and treated with injections. If you're concerned, see your GP as soon as possible, as certain problems caused by the condition can be irreversible if left untreated.'

5. Vitamin D deficiency

You know that Vitamin D is important for healthy bones and teeth, but you might be surprised to know that research has linked a lack of the vitamin with a host of issues, including heart disease, depression, and chronic fatigue syndrome.

'Although we get some vitamin D from our diet, in foods such as oily fish, eggs and fortified cereals, the body needs exposure to sunlight in order to produce sufficient quantities,' says Dr Reddingius.

'Get into the sun for at least 20 minutes every day if you can. If that's not possible, in the winter months for example, consider taking a supplement. Combine a vitamin D supplement with calcium, and it will also help to keep your bones strong.'

6. Post-viral fatigue

Post-viral fatigue syndrome can occur after a viral infection, such as the flu or glandular fever. Symptoms may include chronic tiredness, muscle pain, weight loss, vomiting, diarrhoea, a fever or chills, chest pain and shortness of breath.

'The symptoms of PVFS are not uncommon, particularly following a significant illness. While the effects can be debilitating, PVFS generally gets better slowly over time. While you need to pace yourself, try to stay as active as possible,' advises Dr Reddingius.

'In extreme cases, post-viral fatigue can turn into chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME – a long term debilitating form of fatigue).'

7. Glandular fever

Glandular fever is a common viral infection that typically affects teenagers and young adults. Symptoms include fatigue, fever, a severe sore throat and swollen glands in the neck.

Dr Reddingius says: 'It's caused by the Epstein-Barr virus (EBV), which is found in the saliva of infected people and can be spread through kissing, exposure to coughs and sneezes and sharing eating and drinking utensils.

'Although symptoms are unpleasant they usually clear up within three to four weeks, but occasionally the fatigue can last for several more months.'

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